Patient interface system

ABSTRACT

A patient interface system for scanning a volume of tissue protruding from a patient, the system comprising: a base including a planar portion configured to support the patient in a prone configuration, and a frustoconical portion extending from the planar portion and defining a base aperture configured to receive the volume of tissue; and a support assembly configured to couple to the base, including a frame and a membrane retained in tension within the frame at a peripheral portion of the membrane, wherein the membrane defines a membrane aperture configured to align with the base aperture, and wherein the membrane is configured to deflect into the frustoconical portion of the base in response to the patient&#39;s weight. The system can further include an electrical subsystem including a pressure sensor array configured to generate signals in response to a pressure distribution resulting from the patient&#39;s weight at the patient interface system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/778,985 filed Mar. 13, 2013, which is incorporated in itsentirety herein by this reference.

TECHNICAL FIELD

This invention relates generally to the medical technology field, andmore specifically to a new and useful patient interface system in themedical technology field.

BACKGROUND

Early detection of breast cancer and other types of cancer typicallyresult in a higher survival rate. Despite a widely accepted standard ofmammography screenings for breast cancer detection, there are manyreasons that cancer is often not detected early. One reason is lowparticipation in breast screening, as a result of factors such as fearof radiation and discomfort. In particular, the mammography procedureinvolves compression of the breast tissue between parallel plates toincrease the X-ray image quality by providing a more uniform tissuethickness and stabilizing the tissue. However, this compression istypically uncomfortable, or even painful. Mammography has additionaldrawbacks, such as limited performance among women with dense breasttissue and a high rate of “false alarms” that lead to unnecessarybiopsies that are collectively expensive and result in emotional duressin patients.

Ultrasound tomography is one imaging modality in development that may bea practical alternative to mammography. However, there is a need tocreate a new and useful patient interface system for scanning a volumeof tissue in this manner that is safe and comfortable for patients. Thisinvention provides such a new and useful patient interface system.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is an overall perspective view of a schematic of an embodimentof the patient interface system;

FIG. 1B depicts an elevation view of a pendulous breast interfacing withan embodiment of the system;

FIG. 1C depicts a side view of a pendulous breast interfacing with anembodiment of the system, including exposure of a patient's axilla andchest wall through a taut membrane;

FIG. 2A is an exploded view of a schematic of an embodiment of thepatient interface system;

FIG. 2B is a top view of a portion of an embodiment of the patientinterface system;

FIG. 2C is a side cross-sectional view of a schematic of an embodimentof the patient interface system;

FIG. 3 is a side view of a schematic of the base of an embodiment of thepatient interface system;

FIG. 4 is a perspective cross-sectional view of a schematic of anembodiment of the patient interface system;

FIGS. 5A and 5B are a perspective cross-sectional view of a schematic ofthe support assembly and a cross-sectional view of a schematic of theframe of the support assembly, respectively, of an embodiment of thepatient interface system;

FIG. 5C is a top view of an embodiment of a portion of the supportassembly; and

FIG. 6 is a schematic of a pressure sensor array in a variation of thepatient interface system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of preferred embodiments of the invention isnot intended to limit the invention to these preferred embodiments, butrather to enable any person skilled in the art to make and use thisinvention.

1. System

As shown in FIGS. 1A-3, an embodiment of a patient interface system 100for scanning a volume of tissue protruding from a patient includes: abase 110 including a planar portion 112 on which the patient can lieprone and a frustoconical portion 120 with a sloped inner surface 122and defining a base aperture 114 configured to receive the volume oftissue; and a support assembly 130 coupled to the base 110 including aframe 140 and membrane 150 disposed within the frame 140 and defining amembrane aperture 152 aligned with the base aperture 114 for receivingthe volume of tissue. The frame 140 of the support assembly 130 ispreferably coupled to the frustoconical portion 120 of the base andpreferably surrounds the base aperture 114. The membrane 150 of thesupport assembly 130 is preferably disposed within the frame 140 andconfigured to conform to the body wall of the patient (therebyincreasing access to the volume of tissue) and deflect into the slopedinner surface of the base in response to weight of the patient. In oneembodiment, the support assembly 130 and/or membrane 150 can be selectedfrom a set of support assemblies and/or membranes that are sizeddifferently (e.g. different sizes of membrane aperture 152) to allowoptimization for patients of differing builds. The system 100 canfurther include a table topper 116 configured to couple to planarportion 112 of the base 100, and a pressure sensor array 160 distributedproximal to a patient contact surface of the support assembly 130,wherein the pressure sensor array 160 is configured to generate signalsthat facilitate patient alignment in response to the weight of thepatient. In still other embodiments, the system 100 can additionallyinclude a processor 170 configured to generate an analysis based uponsignals generated by the pressure sensor array 160, and a retainingmodule 180 configured to retain the patient in a desired configurationat the patient interface system 100.

The patient interface system 100 functions to position a patient andvolume of tissue in place for an image scan, in order to ensure properpatient positioning and to facilitate a reduction in the amount ofunnecessary scans taken (e.g., due to patient misalignment). In oneembodiment, as shown in FIGS. 1A, 1B, 1C, and 2A, the patient interfacesystem 100 is configured to be placed over an ultrasound imaging tank102, which receives the volume of tissue extending through the membraneand base apertures 114,152 during an ultrasound tomographic scan, suchas for imaging breast tissue or any other suitable volume of tissue thatcan extend through the table aperture 114 and membrane aperture 152. Asshown in FIGS. 1B and 1C, embodiments of the system 100 preferably allowaccess to a patient's chest wall and axilla, in order to facilitatescanning of a protruding tissue of the patient (e.g., breast tissue. Inparticular, the patient interface system 100 preferably allows a ringtransducer 104 surrounding the extended breast tissue to have morecomplete access to the tissue up to the chest wall of the patient. Thering transducer 104 can be a ring transducer 104 as described in U.S.application Ser. No. 13/756,851 entitled “System and Method for Imaginga Volume of Tissue” and filed on Feb. 1, 2013, which is incorporatedherein in its entirety by this reference, or any other suitable ringtransducer 104. Furthermore, embodiments of the system 100 can enableaccess to and scanning of any other suitable tissue of a patient.

The patient interface system 100 is preferably modular to provide acustomizable interface for various patients of differing builds, andcomfortable for patients to encourage regular screenings and earlycancer detection. The patient interface system 100 can alternatively benon-modular. Additionally, the patient interface system 100 can be usedin conjunction with any suitable imaging modality, or for any suitablepurpose involving substantially complete access to volume of tissue(e.g., for scanning using another imaging modality, for biopsy, forsurgical procedures, etc.).

The base 110 functions to support the weight of a prone patient, and ispreferably configured to provide a surface that spans the entire heightand width of the patient, such that the patient's entire body can besupported within the surface of the base. However, the base no canalternatively be configured to provide a surface that is shorter thatthe height of the patient and/or narrower than the width of the patient,such that portions of the patient's body are not supported by the baseno. The base 110 preferably includes a planar portion 112 on which thepatient can lie prone, and a frustoconical portion 120 with a slopedinner surface 122 configured to provide comfort and allow the volume oftissue to extend into the base aperture 114. As such, the frustoconicalportion 120 preferably terminates at the base aperture 114, whichprovides an opening into the ultrasound imaging tank 102 configured toreceive the volume of tissue and facilitate scanning of the volume oftissue. The base aperture 114 is preferably circular, but in alternativeconfigurations, the base aperture 114 can alternatively be ellipsoidal,oblong, polygonal, or any other suitable shape. In variations, thefrustoconical portion 120 and the base aperture 114 are preferablyconfigured to receive and accommodate a single breast of the patient;however, in other variations, the base 110 can be configured toaccommodate two breasts and/or multiple protruding tissues (e.g., aface, knees, buttocks, etc.) of the patient, for example, by way ofmultiple apertures, multiple frustoconical portions, multiple portionsdisplaced from the planar portion 112 of the base, and/or any othersuitable element(s) configured to accommodate multiple tissue volumes ofthe patient. Furthermore, the base 110 can be configured to accommodatea head region of a patient, for instance, with an aperture configured toreceive and support a region of a patient's head or face (e.g., acoronal region, a sagittal region, a horizontal region, etc.), as thepatient interfaces with the base no (e.g., in configuration wherein thepatient is lying face down, lying on his/her side, lying face up, and/orin any other configuration).

The planar portion 112 and frustoconical portion 120 are preferablyseparate pieces configured to couple to one another, throughcomplementary nesting (e.g., frustoconical portion 120 seated within arecessed cavity or on a shelf of the planar portion 112), interlockingjoints, fasteners, by press fit, using adhesives, using magnets, usingthermal bonding, or in any suitable manner. In variations wherein theplanar portion 112 and the frustoconical portion 120 are configured tocouple to one another, the planar portion 112 and the frustoconicalportion 120 can thus be configured to permanently couple to each other,or can be configured to reversibly couple to each other. In variationsinvolving reversible coupling, the frustoconical portion 120 can be asubstitutable portion, such that different frustoconical portions 120corresponding to different patient morphologies can be provided at thebase 110 to enhance patient comfort. Alternatively, the frustoconicalportion 120 can be integrally formed (e.g., physically coextensive, ofunitary construction) with one or more parts of the planar portion 112of the base 100, for example, by casting. Furthermore, in somevariations, the base no can include any one or more of: a planarsurface, a contoured surface (e.g., to a patient's body), frustoconicalsurface, and any other suitable surface of combination of surfaces tosuitably support a particular patient size or shape.

In one variation, as shown in FIG. 2B, the base 110 is divided along atleast one of a long axis 117 and a short axis 118, such that the planarportion 112 includes two halves, including a head portion 112 aconfigured to support a superior portion of the patient (e.g., torso,arms, and head) and a foot portion 112 b configured to support aninferior portion of the patient (e.g., legs and feet). However, theplanar portion 112 of the base no can alternatively include twounequally sized pieces (e.g., with a relatively longer head portion 112a or a relatively longer foot portion 112 b), or fewer or more than twopieces (e.g., pieces that allow customization of the base to support theuser's limbs in different configurations, and/or multiple pieces thatallow for angular/linear displacement of portions of the base no atmultiple points along the base). As shown in FIG. 2C, the head portion112 a of the base preferably includes a region 115 that receives or iscoupled to the frustoconical portion 120 and/or the support assembly 130placed on top of the base no. The planar portion 112 is preferablyconfigured to be oriented in a substantially horizontal configuration,but in alternative variations, any portion of the base no can beoriented in and/or adjustable to any suitable relative angle, such as toincrease patient comfort or to increase access to areas of the patientthat are otherwise difficult to access. For instance, the base no and/orthe planar portion 112 can be oriented in a substantially verticalconfiguration (e.g., to form a 75-90° angle in relation to a horizontalplane) for patient comfort (e.g., for patients with back issues). Thebase no and/or the planar portion 112 can additionally or alternativelybe transitioned into a substantially vertical configuration (e.g., toform a 75-90° angle in relation to a horizontal plane) or any otherconfiguration for patient loading, and then transitioned into a desiredconfiguration (e.g., a horizontal configuration) after patient loading,to facilitate imaging in any suitable configuration.

In some embodiments, as shown in FIG. 3, the relative positions andorientations of multiple portions of the base 110 can be adjusted. Inone variation, multiple portions can be coupled to one another in such amanner to allow expansion (e.g., linear expansion) or contraction toaccommodate taller or shorter patients. For example, multiple portionsof the base 110 can be slidingly coupled to one another or to a commontrack (or in any suitable adjustable manner). As another example,additional separate portions of the base 110 can be added or removedfrom a series of base portions to extend or shorten the length of thebase no, such as in the manner of a “drop leaf” table. In this example,each base portion in the series of base portions can include grooves orother features (e.g., protrusions, recesses) that facilitate alignment,and can additionally or alternatively include couplers (e.g., magneticcouplers, locks, straps, brackets, screws, pins, etc.) that reversiblymaintain the position(s) of the base portion(s). In another variation,multiple portions can be coupled with a hinge or common adjustableframework (or in any suitable adjustable manner) to allow angularadjustment of at least part of the base no. The adjustable framework canbe manually or automatically actuated using an actuator, such as aratchet mechanism and/or motor (e.g., in response to signals generatedby the pressure sensor array 160 described below). In examples, the headportion 112 a and the foot portion 112 b can thus be angularly displacedrelative to each other about an axis (e.g., the short axis 118), inorder to tilt the head portion 112 a and/or the foot portion 112 b intoinclining and/or declining configurations. In any of these variations,the base 110 preferably includes a lock (e.g., pin, friction lock, orany suitable mechanism) that secures the multiple portions in theirrelative positions and orientations in a reversible manner. Furthermore,still other variations of the base 110 can additionally or alternativelyinclude multiple sections that can be linearly and/or angularlydisplaced about any suitable axis at any suitable number of positionsalong the base no.

The planar portion 112 of the base preferably includes a rigid materialthat is compliant with the U.S. Food and Drug Administration (FDA)guidelines; for instance, in a specific example, the planar portion 112of the base includes Corian® surfaces (e.g., Corian® Whisper surfacesmanufactured by DuPont™) that are compliant with FDA regulation1770.1010. The material is preferably biocompatible, non-porous, andsanitizable. Furthermore, the material of the planar portion 112preferably does not interfere with ultrasound signals transmitted andreceived using a transducer proximal to the base no and/or the volume oftissue. In other variations, however, the material of the base 110 canbe configured to facilitate reflection of transmitted ultrasound signalsin order to enable enhanced analyses of acoustomechanical properties ofthe volume of tissue, and/or to function as a shield to protect apatient against, for example, harmful types of radiation (e.g., x-rayradiation). However, the planar portion 112 of the base can additionallyor alternatively include any other suitable weight-supportive,biocompatible material.

The frustoconical portion 120 of the base 110 functions to provide arecessed space into which the membrane 150 of the support assembly 130can deflect, particularly when the membrane 150 of the support assembly130 supports the body wall of the patient. The frustoconical portion 120is preferably configured to extend beyond a plane defined by the planarportion 112 of the base 110, and can at least partially define the baseaperture 114 configured to receive the volume of tissue. As shown inFIGS. 2A and 3, the frustoconical portion 120 is preferably in theapproximate shape of a funnel, including a sloped inner surface 122extending between a narrow end terminating at an opening 123 and a widerend opposed to the narrow end. The sloped inner surface 122 ispreferably linearly sloped from the wider end to the narrower end, andin a specific example defines a slope relative to a horizontal plane ofbetween 20 and 60 degrees. However, the sloped inner surface 122 canalternatively include any suitable curvature and/or combination of acurved slope and a linear slope. The frustoconical portion 120 ispreferably oriented such that the narrow end of the frustoconicalportion 120 is located below the wider end, in the orientation shown inFIG. 2A. In one variation in which the planar portion 112 and thefrustoconical portion 120 of the base 110 are separate pieces, theplanar portion 112 and the frustoconical portion 120 each preferablydefine respective, aligned base apertures 114 through which the volumeof tissue can protrude and be accessible from the underside of the base110, in the orientation shown in FIG. 2A. For example, alignment of theapertures 114 can be facilitated by the frustoconical portion 120nesting within a complementary region of the planar portion 112,mechanical alignment keys, visual markings, magnetic elements thatfacilitate alignment, and/or any suitable features.

Similar to the planar portion 112 of the base 110, the frustoconicalportion 120 preferably includes a rigid material that is compliant withthe U.S. Food and Drug Administration (FDA) guidelines. In a specificexample, the frustoconical portion 120 includes a polyethyleneterephthalate glycol-modified (PETG) surface such as a surfacemanufactured by Curbell Plastics™ (e.g., Spectar®/Vivak® surfacesmanufactured by Curbell Plastics™). In another specific example, thefrustoconical portion 120 of the base 110 can include Corian® surfaces(e.g., Corian® Whisper surfaces manufactured by DuPont™ that arecompliant with FDA regulation 1770.1010. The material is preferablybiocompatible, non-porous, and sanitizable. Furthermore, the material ofthe frustoconical portion 120 preferably does not interfere withultrasound signals transmitted and received using a transducer proximalto the base no and/or the volume of tissue. In other variations,however, the material of the base no can be configured to facilitatereflection of transmitted ultrasound signals in order to enable enhancedanalyses of acoustomechanical properties of the volume of tissue and/orto function as a shield to protect a patient against, for example,harmful types of radiation (e.g., x-ray radiation). However, thefrustoconical portion 120 of the base no can additionally oralternatively include any other suitable weight-supportive,biocompatible material that can be processed to form the frustoconicalportion 120.

In one specific example, as shown in FIGS. 2A and 2B, the base nodefines a symmetric obround surface with a long axis 117 and a shortaxis 118, wherein the frustoconical portion 120 is biased toward an endof the long axis 117, in order to accommodate a volume of breast tissueof a prone patient interfacing with the system 100. In the specificexample, the frustoconical portion 120 is aligned with the long axis117, such that the long axis 117 defines an axis of symmetry for thebase aperture 114. In this example, the base 110 is configured to bewider than the width of the patient, such that the patient can shifthis/her lateral position relative to the long axis 117 in order to passeach breast through the medially positioned base aperture 114.Furthermore, in the specific example, the base no is configured to beadjustable at the short axis 118, such that the short axis 118 definestwo halves of the base no that can be adjusted and manipulated relativeto each other (e.g., as in FIG. 3) in order to provide multipleconfigurations (e.g., tilted configurations, expanded configurations,contracted configurations) that can customize the base no to thepatient's body and/or provide better access to the volume of tissue.However, in variations of the specific example, the frustoconicalportion 120 can be unaligned with the long axis 117 (e.g., to target aright or left breast of the patient in a customizable manner), such thatthe frustoconical portion 120 is biased in one direction along an axisparallel to the short axis 118 (e.g., in order to accommodate one breastor the contralateral breast), and/or the base 100 can be unadjustable atthe short axis 118 to provide a fixed configuration of the base no. Infurther variations of the specific example, the frustoconical portion120 can be adjustable in a direction parallel to the short axis 118and/or the long axis 118 (e.g., using a sliding track) in order toaccommodate a single breast of the patient in one configuration, and acontralateral breast of the patient in another configuration of thefrustoconical portion 120.

In some embodiments, the system 100 can additionally include a tabletopper 116 disposed on the planar portion 112 of the base 110. As shownin FIGS. 2A and 4, the table topper 116 can be processed to match thefootprint of the base 110, including an aperture to expose the supportassembly 130. However, the aperture of the table topper canalternatively be configured to hide all or a portion of the supportassembly 130. In one variation, the table topper 116 includes a cushion,such a foam pad (e.g., memory foam) or suitable upholstered cushioning,that provides a comfortable surface for the patient to lie down on. Inone example, the table topper 116 includes a planar slab of medical foamprocessed (e.g. formed, cut, molded, etc.) to match the footprint of thebase no. In other variations, the table topper 116 additionally oralternatively includes a contoured, substantially non-planar surfacethat can position the patient into a more ergonomic or comfortable bodyposition, and/or can position the patient such that the breast tissue isin better position for scanning. In examples of these variations, thetable topper 116 can be processed to define recessed and/or protrudingregions for any one or more of: the patient's chest, the patient'sabdomen, the patient's knees, the patient's feet, and any other suitablebody party of the patient.

The table topper 116 can additionally be one of a set of multiple tabletoppers of various sizes, such that a particular table topper can besubstituted in a modular manner into the patient interface system 100 tooptimally accommodate patients of various morphologies. In alternativevariations, the table topper 116 can include a particulate and/orpliable filling that can be manipulated (e.g., molded) to accommodatedifferent users. As such, the particulate filling can be pushed aroundor molded, for example, within a casing, in order to mold the tabletopper 116 to the patient's body. The table topper 116 preferablyincludes an external non-porous surface that can easily be disinfectedor wiped clean between patients (e.g., vinyl). However, the table topper116 can additionally or alternatively be additionally covered with aprotective cover that can be disposed of and replaced by a new coverafter a patient interfaces with the patient interface system 100.

In a specific example, the table topper 116 includes a polyurethane foamencased within a vinyl covering, wherein the polyurethane foam and thevinyl covering are compliant with the U.S. Food and Drug Administration(FDA) guidelines. The polyurethane foam is processed to be waterrepellant, and is biocompatible and sanitizable. Furthermore, thematerial of the table topper 116 preferably does not interfere withultrasound signals transmitted and received using a transducer proximalto the base 110 and/or the volume of tissue. In other variations of thespecific example, however, the material of the table topper 116 can beconfigured to facilitate reflection of transmitted ultrasound signals inorder to enable enhanced analyses of acoustomechanical properties of thevolume of tissue, and/or can function as a shield in variations of thesystem 100 configured to interface with imaging modalities involving,for example, more harmful forms of radiation (e.g., x-ray radiation).However, the table topper 116 can additionally or alternatively includeany other suitable conforming, biocompatible material that facilitatespatient comfort when interfacing with the system 100.

The support assembly 130 functions to simultaneously facilitate patientcomfort and to allow a volume of tissue of the patient to extend throughthe base aperture 114 into a tank 102 for tissue scanning. The supportassembly 130 includes a frame 140 and a membrane 150 disposed within theframe 140 and configured to conform to the body wall and deflect intothe inner surface of the frustoconical portion 120 of the base 110.Preferably, the support assembly 130 is configured to couple to the base110 such that a membrane aperture 152 of the membrane 150 is alignedwith the base aperture 114, and such that a volume of tissue of thepatient can pass through both the membrane aperture 152 and the baseaperture 114. The support assembly 130 can be one of a set of multiplesupport assemblies that include membrane apertures of various sizesand/or locations relative to the frame 140, such that a particularsupport assembly 130 can be reversibly substituted in a modular mannerinto the patient interface system 100 to accommodate variations inpatient morphology. For example, a first support assembly 130 caninclude a larger membrane aperture 152 for scanning a breast of apatient with larger breasts, and a second support assembly 130 caninclude a smaller membrane aperture 152 for scanning a breast of apatient with smaller breasts. In other variations, however, the supportassembly 130 can be a non-substitutable element of the system 100, andcan still accommodate variations in patient morphology in any othersuitable manner. For instance, the support assembly 130 can include aset of pre-cut inserts (e.g., inserts with different sized apertures,inserts with different material properties, etc.) that can be positionedsuperior to or inferior to the membrane 150 and aligned relative to themembrane aperture 152 in any suitable manner, in order to accommodatedifferent sized breasts without requiring the tension of the membrane tobe adjusted. In still other variations, however, the support assembly130 may not be configured to accommodate variations in patientmorphology.

In another example, different support assemblies 130 can includedifferent numbers and/or configurations of membrane apertures 152 foraccommodating both breasts of a patient and/or other tissues of apatient. In an alternative variation, the patient interface system 100includes a frame 140 and a membrane 150 that is one of a set of multiplemembranes, such that a particular membrane 150 can be swapped in amodular manner to couple to the frame 140. In examples, a first membraneconfigured to be retained within the frame 140 can include a largermembrane aperture 152 for scanning a breast of a patient with largerbreasts, and a second membrane configured to be substituted for thefirst membrane can include a smaller membrane aperture 152 for scanninga breast of a patient with smaller breasts. In another example of thisalternative variation, membranes can include different numbers and/orconfigurations of membrane apertures 152 for accommodating both breastsof a patient and/or other tissues of a patient. Thus, in thesealternative embodiments, the support assembly includes a single frame140 and replaceable membranes 150 that are configured for differentapplications. However, the patient interface system 100 can include anysuitable number of frames and/or membranes 150 that can be combined inany suitable manner to optimize position, comfort, and/or scanningaccess to the tissue for various patients.

The frame 140 of the support assembly 130 functions to providestructural support to the membrane 150 and couples the membrane 150 tothe base no. The frame 140 can additionally function to maintain themembrane 150 in tension at a peripheral portion of the membrane 150,such that the membrane 150 provides a counteracting force in response tothe weight of the patient's body. However, in some variations, the frame140 may not be configured to retain the membrane 150 in tension. Theframe 140 is preferably annular, forms a closed perimeter about themembrane 150, and can be circular or ellipsoidal; however, the frame 140can alternatively form an open perimeter about a portion of the membrane150 and/or define any other suitable shape (e.g., regular polygonalshape, irregular polygonal shape, irregular curvilinear shape).

As shown in FIGS. 5A and 5B, the frame 140 preferably includes at leasta frame base 142, which functions to provide coupling locations tosecure the membrane 150 to the frame 140 in a reversible manner. In somevariations, the frame base 142 can additionally or alternativelyfunction to provide surfaces that allow coupling of the membrane 150 tothe frame 140 in a reversible manner. The frame base 142 preferablycouples to or abuts the frustoconical portion 120 of the base no at aninferior surface 147 of the frame base 142, but can additionally oralternatively couple to the planar portion 112 or other suitable portionof the base no. In one example, as shown in FIGS. 2A-2C and 5A-5B, theframe base 142 is preferably annular and configured to nestle and beseated within an annular recess 143 formed circumferentially between thefrustoconical portion 120 and the planar portion 112 of the base 110,such that an inferior surface of the frame base 142 abuts thefrustoconical portion 120. In the example, the frustoconical portion 120is configured to define two perpendicular walls of the annular recess143, and the planar portion 112 is configured to define a third wall ofthe annular recess 143, wherein the third wall is substantially opposedto and/or concentric with one of the walls defined by the frustoconicalportion 120. However, the frame base 142 can alternatively be configuredto be seated within an annular recess defined circumferentially in thefrustoconical portion 120, within an annular recess definedcircumferentially in the planar portion 112 of the base no, or within arecess defined by the frustoconical portion 120 and/or the planarportion 112 in any other suitable manner. In some variations of theexample, the recess and/or corresponding mating portion of the framebase 142 can be non-annular, the frame base 142 can be configured toonly be partially seated within the recess, and the frame base 112 andthe recess can be configured for coupling in any other suitable manner.In still other variations, the frame base 142 can couple to the base nowith a snap fit, press fit, friction fit, latches, straps, magneticelements, and/or in any suitable manner. Furthermore, the frame base 142and/or the base no can include alignment features to orient the supportassembly 130 in a particular matter relative to the base no. Suchalignment features can include, for example, visual markings or physicalinterference features (e.g., ellipsoidal shape of the frame, mechanicalkeys, magnetic aligners). In a specific example, the frame base 142includes a rigid polymer, such as polyethylene terephthalateglycol-modified (PETG), but can additionally or alternatively includeany suitable material. In one embodiment, the frame base 142 can beinjection-molded, but can alternatively be milled, 3D-printed, casted,or manufactured in any suitable manner.

The membrane 150 is preferably coupled in tension across the frame 140of the support assembly 130 and configured to be positioned over thefrustoconical portion 120 of the base no when the support assembly 130is coupled to the base no, and preferably defines a membrane aperture152 that receives the volume of tissue. In one variation, the membrane150 includes a flexible polymer such as urethane and can be coupled tothe support assembly 130 using, for example, mechanical fasteners, anadhesive, coupling using magnetic elements, and/or thermal welding.However, the membrane 150 can alternatively include any suitablematerial and be coupled with any suitable fixation method. When apatient lies prone on the table surface and the volume of tissue (e.g.,a volume of breast tissue) extends through the membrane aperture 152,the membrane 150 preferably deflects downward into the inner slopedsurface 122 of the frustoconical portion 120 of the base no and conformsto the body wall around the volume of tissue, due to the weight of thepatient on the support assembly 130. The membrane 150 is preferably oneof a set of membranes with varying dimensions, such as in size, shape(e.g., circular, ellipsoidal, rectangular), number of apertures, andlocation (e.g., centered or off-centered relative to the frame 140 orrelative to the base no) of the membrane aperture 152. The set ofmembranes can additionally or alternatively vary in any suitable aspect,such as material type or thickness. For example, material type can varyto accommodate patients with skin contact allergies, or can be stronger(e.g., have a higher tensile modulus, have greater fracture resistance)to provide extra patient support without requiring a substantiallythicker membrane 150.

As shown in FIG. 5B, the support assembly 130 can further include abezel 144 or rim coupled to the frame base 142 (e.g., a superior surfaceof the frame base 142) and circumferentially surrounding the membrane150. The bezel 144 functions to facilitate coupling of the membrane 150to the frame 140, such that the membrane 150 can be retained between theframe base 142 and the bezel 144 at a peripheral portion of the membrane150. The bezel 144 is thus preferably a separate piece from the framebase 142, but can alternatively be integrally formed with the frame base142 or other component of the support assembly 130 in a manner thatallows a portion of the membrane 150 to be seated between the bezel andthe frame base 142 or other component of the support assembly 130. Forexample, the bezel 144 and the frame base 142 can be integrally formedalong an edge, in a manner that provides a circumferential gap betweenthe bezel 144 and the frame base 142, wherein the circumferential gapcan receive the membrane 150.

The bezel 144 is preferably proximal to a superior surface 149 of theframe base 142 by a series of rivets or other mechanical fasteners 141distributed around the border of the support assembly 130. Therivets/mechanical fasteners can provide a compressive force that retainsthe membrane 150 between the bezel 144 and the frame base 142, and/orcan pass through openings in the membrane 150 to lock the membrane inplace relative to the bezel 144 and the frame base 142. The series ofmechanical fasteners 141 are preferably arranged uniformly about theborder of the support assembly 130, but can additionally oralternatively include fasteners that are clustered or randomlydistributed about the border of the support assembly 130. For example,in one variation, a series of mechanical fasteners sandwiches themembrane 150 between the bezel 144 and the frame base 142, therebysecuring the membrane 150 to the support assembly 130. However, theseries of mechanical fasteners may not provide a compressive force, butmay instead bias the bezel 144 toward the frame base 142 while couplinga peripheral portion of the membrane 150 between the bezel 144 and theframe base 142 (e.g., a fastener can be configured to pass through anopening in the membrane that is aligned with openings in the bezel 144and the frame base 142). Additionally or alternatively, the bezel 144can couple to the frame 140 with a snap fit, an adhesive, magneticcouplers, or any suitable fastening mechanism. The bezel 144 preferablyincludes the same material as the frame base 142, but can alternativelyinclude one or more materials that are different from the frame base142.

In one variation, as shown in FIG. 5B, the support assembly 130 can alsoinclude a tensioning ring 146, disposed adjacent to the membrane 150, ata radially inner side of the bezel 144 for maintaining the tensionacross the membrane 150. In particular, the tensioning ring 146 ispreferably arranged concentrically with the frame base 142 and/or bezel144 and underneath the membrane 150 in the orientation shown in FIG. 5B,such that the membrane 150 is stretched in suitable tension to supportthe patient weight. As such, in the orientation shown in FIG. 5B, aperipheral portion of the membrane 150 is retained between thetensioning ring 146 and the bezel 144 in order to maintain tensionacross the membrane 150.

The amount of membrane tension can be fixed and dependent on, forexample, the thickness of the tensioning ring 146, and/or of a spacer148 configured to displace the tensioning ring 146 from the frame base142, wherein an increased height of the spacer 148/tensioning ring 146can result in greater tension and a decreased height of the spacer148/tensioning ring 146 can result in reduced tension. In somevariations, the tensioning ring 148 and/or the spacer 148 can besubstitutable elements, such that the amount of tension across themembrane can be manipulated by using tensioning rings 146 and/or spacers148 of different thicknesses. The spacer 148 is preferably annular andconfigured to match a footprint of the tensioning ring 146; however, thespacer 148 can alternatively be defined by any other suitable geometryand/or footprint. For example, the spacer 148 can define anon-continuous surface that abuts the tensioning ring 146 at certainlocations. The amount of membrane tension can additionally oralternatively be adjustable, such as to maintain a particular desiredamount of tension over repeated stress on the membrane 150 due torepeated uses of the support assembly 130. For example, the thickness orelevation of the tensioning ring 146 and/or of the spacer 148 can beadjusted (e.g., using a mechanism to expand the thickness of thetensioning ring 146 and/or the spacer 148) to obtain a suitable amountof membrane tension. The tensioning ring 146 and/or spacer 148 caninclude the same material as the frame base 142, but can alternativelyinclude one or more materials that are different from the frame base142. The support assembly 130 can, however, include any other suitableelement(s) for maintaining and/or adjusting tension across the membrane150.

In a variation omitting a spacer 148, the membrane 150 can be configuredto be retained at one of a set of peripheral regions 157, as shown inFIG. 5C, wherein each peripheral region of the set of peripheral regions157 includes an annular band of the membrane 150. As such, retaining aradially inner band of the set of peripheral regions can contribute toincreased tension across the membrane 150, and retaining a radiallyouter band of the set of peripheral regions can contribute to decreasedtension across the membrane 150. As such, the membrane 150 can beretained at a peripheral region between the bezel 144 and the frame base142, or in any other suitable manner. Furthermore, variations of thesupport assembly 130 can, however, include any suitable combination ofthe above described variations and examples. For example, a variation ofthe support assembly 130 can include a spacer 148 and a membrane 150with a set of peripheral regions 157, such that the tension across themembrane 150 can be adjusted using at least one of two features. Instill other variations, the system 100 can entirely omit elements thatfacilitate tensioning of the membrane 150. For example a patient'sweight can provide an amount of tension that allows the patient'sbreast, axilla, and chest wall to protrude through the membrane aperture152, in variations of the system 100 for imaging a volume of breasttissue.

In one embodiment of the system 100, as shown in FIG. 6, the supportassembly 130 additionally includes an electrical subsystem coupled tothe base 110 and/or support assembly 130. In one variation, theelectrical subsystem can include a pressure sensor array 160 distributedon a patient contact surface of the support assembly 130. For example,the pressure sensor array 160 can be embedded in a sheet coupled to theframe base 142 and/or membrane 150, such that multiple pressure sensors162 are distributed around the support assembly 130 and are configuredto generate signals in response to the patient's weight and/or inresponse to a distribution of the patient's weight across the membrane150. The sheet can include a flexible polymer such as urethane,preferably similar to the membrane 150. However, the pressure sensorarray 160 can be configured relative to the frame base 142 and/or themembrane 150 in any other suitable manner. Furthermore, the pressuresensor array 160 can include any suitable number of pressure sensors inany suitable configuration (e.g., evenly distributed, distributed in aclustered manner, distributed randomly, distributed in a radialconfiguration, etc.) relative to the base 110 and/or the supportassembly 130.

In some variations, the electrical subsystem can include a conditioningmodule 164, which functions to preprocess signals generated by thepressure sensor array 160 prior to transmission to a processor 170. Theconditioning module 164 preferably comprises signal conditioningelements, including one or more of: an analog-to-digital converter(e.g., to convert analog signals from the pressure sensor array 160), anamplifier, and a filter for processing signals prior to transmission. Insome variations, the conditioning module 164 can include amicroprocessor configured to direct signal conditioning functionalitiesof the conditioning module 138 and a voltage regulator configured toprotect elements of the electrical subsystem from overvoltage and/orunder-voltage states.

In one variation, the pressure sensor array 160 can be used to confirmapplication of approximately uniform pressure at the membrane 150 (e.g.,at a peripheral portion of the membrane, across the membrane) from thepatient weight. For example, the pressure sensor array 160 can be usedto confirm that the body wall of the patient is seated as evenly on themembrane 150 as possible and the volume of tissue is extended as fullyas possible through the membrane aperture 152, thereby facilitating acomplete imaging scan of the volume of tissue. Alternatively, thepressure sensor array 160 can be calibrated to a certain non-uniformpressure distribution that provides a desired patient configurationrelative to the patient interface system 100, which can be used tomaintain any suitable position of the patient to achieve good scanningresults. In still other variations, the pressure sensor array 160 can beused for any suitable purpose, or variations of the system can entirelyomit the pressure sensor array 160. Furthermore, the electricalsubsystem can additionally or alternatively include any other suitableelectrical components.

In variations of the system 100 including a pressure sensor array 160,the system 100 can include a processor 170, which functions to receive aset of signals from the pressure sensor array 160 and/or the signalconditioning module 164, and to generate an analysis of the set ofsignals in order to guide patient placement at the patient interfacesystem 100. The processor 170 can thus comprise a first module 171configured to receive the set of signals from the pressure sensor array160, and a second module 172 configured to generate an analysis from theset of signals. In a first example, the analysis can confirm a uniformpressure distribution resulting from the patient's weight at the patientinterface system 100. In a second example, the analysis can confirm adesired non-uniform pressure distribution resulting from the patient'sweight at the patient interface system 100. In another example, theanalysis can confirm an undesired uniform pressure distribution and/oran undesired non-uniform pressure distribution resulting from thepatient's weight at the patient interface system 100. A uniform pressuredistribution and/or a non-uniform pressure distribution confirmed by theanalysis can then be used to guide or adjust the patient's configuration(e.g., torso position, body wall position, etc.) in order to facilitatescanning.

In some variations, guidance can be provided, as facilitated by theanalysis generated by the processor 170, using visual and/or audio meansfor transmitting information. In one example, the analysis can be usedto generate a rendering at a user interface 185 including a displayconfigured to depict a current position of the patient, and a desiredposition of the patient that will produce a more desired pressuredistribution. In another example, the analysis can be used to provideaudio or text-based instructions to the patient and/or an operator(e.g., using a visual display, using a speaker), wherein theinstructions facilitate adjustment of the patient's configurationrelative to the patient interface system 100. In another example, theinstructions can provide suggested system 100 configurations includingone or more of: tilt angles of the planar portion 112 and/or thefrustoconical portion 120 of the base 110, expanded and/or contractedconfigurations of the base 110, appropriate membrane sizes, appropriatemembrane aperture sizes, appropriate tensioning ring 146 and/or spacer148 thicknesses to achieve a desired tension across the membrane 150,and any other suitable configuration of any element of the system 100.Furthermore, in some variations of the example, the instructions can beprovided to a controller 178 configured to automatically adjust systemelement configurations (e.g., tilt angles of the planar portion 112and/or the frustoconical portion 120 of the base 110, expanded and/orcontracted configurations of the base 110, appropriate membrane sizes,appropriate membrane aperture sizes, appropriate tensioning ring 146and/or spacer 148 thicknesses, etc.) using an actuation subsystem 179configured to manipulate a configuration of at least one element of thesystem 100.

As shown in FIG. 1, the system 100 can additionally include a retainingmodule 180, which functions to retain the patient in a desiredconfiguration once the patient has been properly positioned relative tothe patient interface system 100. The retaining module 180 can directlyretain the patient's torso in a specific configuration, or canadditionally or alternatively retain one or more of the patient'slimbs/extremities to constrain patient motion. In some variations, theretaining module 180 can additionally or alternatively retain thepatient's head/neck in a specific configuration to further limit patientmovement. As such, the retaining module 180 can include one or more of:a belt, a strap, a cuff, a band, and any other suitable retainingelement. The retaining module 180 preferably includes adjustableelements (e.g., adjustable straps, elastic bands, etc.) configured toprovide an amount of restraint that constricts motion of the patientwhile still allowing patient comfort. The retaining element(s) can becoupled to the base no, the support assembly 130, the table topper 116,and/or any other suitable portion of the system 100 in a manner thatretains a configuration of the patient relative to the system 100.

Preferred embodiments of the preferred patient interface system 100include every combination of the base 110, the support assembly 130, theprocessor 170, the controller 178, the actuation subsystem 179, and therestraining module 180, and their respective components, including theplanar portion 112 and the frustoconical portion 120 of the base 110,the table topper 116, frame 140, the membrane 150, the tensioning ring146, the spacer 148, the pressure sensor array 160, and the conditioningmodule 164 of the support assembly 130. Furthermore, the system 100 canomit any one or more of the above described elements. For example,variations of the system 100 can omit the pressure sensor array 160, andcan additionally or alternatively omit the tensioning ring(s) 146, thespacer(s) 148, and any other element configured to facilitate tensioningof the membrane 150.

2. Exemplary Use

In an exemplary use of an embodiment of the patient interface system,the patient interface system positions the breast of a patient to bescanned for ultrasound tomography. This example implementation is forillustrative purposes only, and should not be construed as definitive orlimiting in scope of the claimed invention. In this example, a systemoperator or other translates various measurements of the patient into aselection of a suitable support assembly to be coupled to the base.These measurements can include any one or more of: breast size, patientweight, patient height, torso width, torso length, and any othersuitable measurement, and correspond to a support assembly with at leasta particular size of membrane aperture, and possibly to a particular setof adjustments to the base. The patient lies prone, stomach-side down,on the cushion of the base, and is positioned such that the breast to bescanned extends through the membrane aperture (and the aligned one ormore apertures associated with the base) and into an imaging tank filledwith water and an ultrasound transducer. Data generated from a pressuresensor array embedded in a flexible sheet coupled to the membrane andanalyzed by a processor can be used to confirm proper positioning of thepatient, and/or can be used to reposition the patient relative to thepatient interface system, in order to improve data quality capturedusing the ultrasound transducer. The processor can generate a renderingthat is displayed at a user interface accessible to at least one of thepatient and the system operator, in order to guide positioning and/orrepositioning of the patient at the patient interface system. Theultrasound transducer can then be activated to scan the breast tissuewhile the patient interfaces with the patient interface system, andacoustic data from the transducer can be analyzed by the processorand/or any suitable other processor to generate renderings of the breastbased on one or more acousto-mechanical parameters including: acousticreflection, acoustic attenuation, acoustic speed, and combinationsthereof.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. A patient interface system for scanning a volume of tissueprotruding from a patient, the system comprising: a base including aplanar portion configured to support the patient in a proneconfiguration, and a frustoconical portion extending from a planedefined by the planar portion and defining a base aperture configured toreceive the volume of tissue; a support assembly configured to couple tothe base, including a frame configured to abut to the frustoconicalportion of the base and a membrane retained in tension within the frame,wherein the membrane defines a membrane aperture configured to alignwith the base aperture, and wherein the membrane is configured todeflect into the frustoconical portion of the base in response to thepatient's weight; and a pressure sensor array disposed proximal to atleast one of the membrane and the frame, and configured to generate aset of signals in response to a distribution of the weight of thepatient at the patient interface system.
 2. The system of claim 1,wherein at least a portion of the frustoconical portion of the base isconfigured to be seated within a recessed cavity on a shelf of definedby the planar portion of the base.
 3. The system of claim 2, wherein theframe includes a frame base, a bezel configured to abut a superiorsurface of the frame base, thereby forming a gap configured to receivethe membrane, and a tensioning ring disposed at a radially inner surfaceof the bezel, wherein a peripheral portion of the membrane is configuredto be retained within the gap, and wherein the membrane is furtherconfigured to be retained at the radially inner surface of the bezel bythe tensioning ring, in order to maintain tension across the membrane.4. The system of claim 3, further comprising a spacer configured todisplace the tensioning ring from the frame base, thereby adjustingtension across the surface of the membrane.
 5. The system of claim 1,wherein the pressure sensor array includes a set of sensors, uniformlydistributed in a radial configuration within a flexible sheet incommunication with at least one of the membrane and the frame.
 6. Thesystem of claim 1 further including a processor configured to generatean analysis derived from signals generated by the pressure sensor array,wherein the analysis is configured to facilitate positioning of thepatient at the patient interface system to achieve a desired patientconfiguration.
 7. The system of claim 6, wherein the processor isfurther configured to provide instructions, configured to guidepositioning of the patient, at a user interface for at least one of thepatient and an operator of the system, based upon the analysis.
 8. Thesystem of claim 6, further comprising a controller configured toautomatically adjust a configuration of at least one of the base and thesupport assembly in response to the analysis, thereby achieving thedesired patient configuration.
 9. The system of claim 1, furthercomprising a ring-shaped transducer array positioned proximal the baseaperture, comprising a set of ultrasound emitters configured to emitacoustic waveforms toward the volume of tissue, and a set of ultrasoundreceivers configured to generate a set of acoustic data based uponacoustic waveforms received from the volume of tissue.
 10. A patientinterface system for scanning a volume of tissue protruding from apatient, the system comprising: a base including a planar portionconfigured to support the patient in a prone configuration, and afrustoconical portion extending beyond a plane defined by the planarportion and defining a base aperture configured to receive the volume oftissue; and a support assembly configured to couple to the base,including a frame base defining a superior surface and an inferiorsurface configured to abut to the frustoconical portion of the base, abezel configured to couple to the superior surface of the frame base andprovide a gap between the superior surface of the frame base and thebezel, and a membrane retained in tension within the gap at a peripheralportion of the membrane, wherein the membrane defines a membraneaperture configured to align with the base aperture, and wherein themembrane is configured to deflect into the frustoconical portion of thebase in response to the patient's weight.
 11. The system of claim 10,wherein the base defines an obround surface, wherein the frustoconicalportion is biased toward an end of a long axis of the base, and whereinthe long axis of the base defines an axis of symmetry for thefrustoconical portion.
 12. The system of claim 10, wherein at least aportion of the frustoconical portion of the base is configured to beseated within a recessed cavity on a shelf of defined by the planarportion of the base.
 13. The system of claim 10, wherein the baseincludes a head portion divided from a foot portion at an axis, andwherein the head portion is configured to be linearly displaced from thefoot portion, and wherein the head portion is configured to be angularlydisplaced from the foot portion about the axis to produce a tiltedconfiguration of the base.
 14. The system of claim 10, wherein thesystem further includes a table topper, including an encased pliablematerial, disposed upon the planar portion of the base.
 15. The systemof claim 10, wherein the frame base of the support assembly isconfigured to couple to at least one membrane of a set of membranes,wherein the set of membranes includes the membrane, and wherein eachmembrane in the set of membranes defines a membrane aperture differentin size from every other membrane aperture in the set of membraneapertures.
 16. The system of claim 10, further comprising a tensioningring disposed at a radially inner surface of the bezel, wherein aperipheral portion of the membrane is configured to be retained withinthe gap by a set of couplers configured to bias the bezel toward theframe base, and wherein the membrane is further configured to beretained at the radially inner surface of the bezel by the tensioningring, in order to maintain tension across the membrane.
 17. The systemof claim 16, further comprising a spacer configured to displace thetensioning ring from the frame base, thereby adjusting tension acrossthe surface of the membrane.
 18. The system of claim 16, wherein theframe base is an annular frame base and is configured to be seatedwithin an annular recess formed circumferentially between thefrustoconical portion and the planar portion of the base, wherein thefrustoconical portion of the base defines two perpendicular surfaces ofthe annular recess.
 19. The system of claim 10, further including apressure sensor array disposed proximal to a patient contact portion ofthe support assembly, wherein the pressure sensor array includes a setof pressure sensors configured to generate signals in response to adistribution of the patient's weight at least at one of the membrane andthe frame base.
 20. The system of claim 19, further including aprocessor configured to generate an analysis derived from signalsgenerated by the pressure sensor array, wherein the analysis isconfigured to facilitate positioning of the patient at the patientinterface system to achieve a desired patient configuration.